See Sarah Michelle Gellar's Heartfelt Tribute To Shannen Doherty On International Breast Cancer Day

"I am only a footnote in this picture."

Sarah Michelle Gellar continues to support her friend and fellow actress Shannen Doherty as she fights breast cancer. On Wednesday, Gellar recognized International Breast Cancer Awareness Day by paying tribute to both Doherty and her doctor on Instagram.

Gellar shared a photo of herself sitting between Doherty and Dr. Lawrence Piro, her oncologist. "I am only a footnote in this picture," Gellar wrote in the caption. "To my left is @theshando, my friend who is kicking cancer in the you know what. But more than that, she is sharing her battle, so people fighting this horrible disease know they are not alone. I am inspired by her on the daily."

Of Dr. Piro, Gellar wrote, "It's not a job to this incredible doctor, it's his life. I have never been in the company of a more passionate or dedicated scientist. He is the true definition of a hero. I am honored to know you both."

Gellar went on to stress the importance of breast cancer screenings: "Breast cancer is nowadays the most frequent malignant tumor in the world. But with early detection and incredible doctors like Dr Piro, breast cancer can be fought and won. So today I urge you, make an appt to get checked or even remind a friend to get checked or just think pink and honor those fighting this battle today and everyday [sic]."

A photo posted by ShannenDoherty (@theshando) on Jul 25, 2016 at 10:26am PDT

Doherty, who was diagnosed with cancer last year, has been candid about the experience in recent months. She frequently documents her journey on Instagram, from shaving her head to receiving chemotherapy. She told ET Online that she underwent a single mastectomy in May and explained why sharing the details of her battle is so important.

"I wanted to put it out there the way it felt the best for me to put it out there," she said. "And also, if I could help one person then it makes me go, 'Oh OK.' It's easier to live with having cancer if I know I'm helping at least one person."

Doherty's bravery and openness are admirable, and she's lucky to have a friend like Gellar by her side.